Seed priming with selenium and zinc nanoparticles modifies germination, growth, and yield of direct-seeded rice (Oryza sativa L.)

Abstract

Direct-seeded rice (DSR) seeds are often exposed to multiple environmental stresses in the field, leading to poor emergence, growth and productivity. Appropriate seed priming agents may help to overcome these challenges by ensuring uniform seed germination, and better seedling stand establishment. To examine the effectiveness of sodium selenite (Na-selenite), sodium selenate (Na-selenate), zinc oxide nanoparticles (ZnO-NPs), and their combinations as priming agents for DSR seeds, a controlled pot experiment followed by a field experiment over two consecutive years was conducted on a sandy clay loam soil (Inceptisol) in West Bengal, India. Priming with combinations of all priming agents had advantages over the hydro-priming treatment (control). All the combinations of the three priming agents resulted in the early emergence of seedlings with improved vigour. In the field experiment, all the combinations increased the plant chlorophyll, phenol and protein contents, leaf area index and duration, crop growth rate, uptake of nutrients (N, P, K, B, Zn and Si), and yield of DSR over the control. Our findings suggest that seed priming with the combination of ZnO-NPs, Na-selenite, and Na-selenate could be a viable option for the risk mitigation in DSR.

Potential Effects of Metal Oxides on Agricultural Production of Rice: A Mini Review

“…In 2021, Sharma et al used ZnO NPs prepared from a Senna occidentalis leaf as a nano-initiator to pre-treat seeds of an early flowering pure mutant to improve rice seed germination, seedling vigor, and zinc content in seedlings [ 77 ] ( Figure 9 a). Adhikary et al adopted the idea and used ZnO NPs and selenium as initiators for rice seeds [ 78 ], which enhanced seed vigor and improved conditions such as poor seedling emergence triggered by direct sowing practiced for rice cultivation in South Asia. In addition, Elshayb et al sprayed ZnO NPs on rice with biochar (BC) as a soil amendment.…”

The Alleviation of Metal Stress Nuisance for Plants—A Review of Promising Solutions in the Face of Environmental Challenges

“…Moreover, priming can be applied to various organs and at various stages of the plant life cycle. The most frequently used is seed priming, which provides faster and more uniform seed germination, ensures efficient nutrient and water uptake, releases photo- and thermo- dormancy, as well as improves seedling vigor in relation to their further growth and yield under both optimal and adverse conditions [ 82 , 83 , 84 ]. Less often, priming concerns seedlings, young plants, or their parts although they show significantly greater tolerance to different abiotic stresses than untreated ones [ 85 , 86 ].…”

“…Additionally, the use of nanopriming had a positive effect on redox homeostasis in wheat plants [ 103 ]. ZnO nanoparticles, sodium selenite (Na-selenite), sodium selenate (Na-selenate), and their combinations as priming agents for direct-seeded rice seeds were also investigated [ 84 ]. It was observed that all tested combinations of the priming agents (10 µmol ZnO-NPs; 50 µmol Na-selenite; 50 µmol Na-selenate; and the following combinations at the mentioned concentrations: Na-selenite + Na-selenate; ZnO-NPs + Na-selenite; ZnO-NPs + Na-selenate; ZnO-NPs + Na-selenite + Na-selenate) resulted in the early emergence of seedlings with increased vigor compared to the control.…”

“…It was observed that all tested combinations of the priming agents (10 µmol ZnO-NPs; 50 µmol Na-selenite; 50 µmol Na-selenate; and the following combinations at the mentioned concentrations: Na-selenite + Na-selenate; ZnO-NPs + Na-selenite; ZnO-NPs + Na-selenate; ZnO-NPs + Na-selenite + Na-selenate) resulted in the early emergence of seedlings with increased vigor compared to the control. Furthermore, in the field experiment, all tested combinations improved the plant growth parameters and yield, which was the result of increased photosynthetic pigments, increased phenol and protein content, and the increased uptake of nutrients such as N, P, and K [ 84 ]. Salam et al [ 80 ] showed that priming maize seeds with ZnO NPs nanoparticles (500 mg/L for 24 h) significantly improved plant growth, biomass, and photosynthesis efficiency under cobalt (Co) stress.…”

Zinc Oxide Nanoparticles Improve Salt Tolerance in Rice Seedlings by Improving Physiological and Biochemical Indices

“…This increases in population may enhance food demand [1,2]. Continuously growing human population and changes in climate due to global warming may affect the prevailing farming practices, reducing crop production [2,3]. Currently, one-third of world agricultural lands suffer from salinization due to inappropriate agrochemical and Agriculture 2022, 12, 1014 2 of 21 agriculture practices, and industrial pollution also exacerbates this problem [4,5].…”